P1629 With newly installed built trans

Ok, so I bought a clubgp members old built trans a couple months back. Finally got around to installing it this past weekend. It ran last night enough to get around the block(did the swap at my friends house). So I go to pick it up today and it won't stay running for more than 5 seconds and shuts off. The car is a gt and the old trans had 3.29's in the stock trans. What needs to change in the PCM to make the trans be recognizable by the PCM? The trans also has a zzp 2500 stall tc, if that means anything. I am not one to know anything about tuning, but i am more than willing to do whatever it takes to learn everything possible.

Please help me out with as much info as possible!

thank you in advance!!

What gear ratio is in the built trans? You'll need to change that, just guessing if it's from a GTP it'll have 2.93s unless they changed the ratio.